Victims of illegal immigrant violence released a letter Monday demanding Republican voters reject Sen. Marco Rubio’s presidential campaign, saying he made himself unacceptable by pushing for “amnesty” in 2013.

“The inconvenient truth is that we have been betrayed by politicians,” the letter, from the Remembrance Project said.

More than three dozen people whose relatives were killed by illegal immigrants signed onto the letter.

“We do not want other families to die at the hands of illegal aliens,” the victims wrote. “We are pleading with the Republican voter: Reject Rubio. Send a message to every politician in Washington D.C.: if you betray American citizens, you will never occupy the Oval Office.”

Mr. Rubio’s presidential campaign has been dogged by his work on the 2013 immigration bill, where he was part of the “Gang of Eight” senators who wrote legislation that would have legalized most of the 11 million illegal immigrants in the country.

Many of the letter-writers’ relatives were killed by illegal immigrants driving drunk. The 2013 immigration bill, as written, would have allowed some illegal immigrants with drunken-driving convictions to get on the same pathway to citizenship as other illegal immigrants, according to an analysis by the Center for Immigration Studies.

The letter-writers said Mr. Rubio never reached out to them during the writing of the bill.

Mr. Rubio says he learned his lesson from the 2013 fight, saying he now believes that security and stricter immigration enforcement must come before legalization.

But GOP front-runner Donald Trump and fellow candidate Sen. Ted Cruz have said Mr. Rubio was on the wrong side of the debate the last time the issue came to Congress.